The Clinical Course of Viral Hepatitis

A non-radioactive diagnostic test for the detection of HBV DNA sequences in serum at the single molecule level

A non-radioactive diagnostic test, using an acetylaminofluorene-labelled DNA probe, was developed to detect HBV DNA sequences in serum. In vitro enzymatic amplification was employed to increase the amount of HBV DNA sequences, and an amplification rate up to 1.5 x 10(7) was observed. When a dot-blot was performed after amplification with the Klenow fragment for 32 cycles, the detection limit was 3-30 particles. Sera from 20 blood donors and 10 HBs-Ag carriers were screened simultaneously, with the non-radioactive test performed after 28 amplification cycles, and with the classical radioactive test without amplification. An acceptable correlation was obtained between these two techniques. In Southern blot analysis of samples amplified with the thermoresistant DNA polymerase (Taq polymerase) for 40 cycles, a single DNA molecule was detected. Thermal treatment at 115 degrees C efficiently disrupted purified viral particles and allowed the detection of a single viral particle. Applied to crude serum, a kinetic study showed that this treatment was optimal after an incubation time of up to 10 min. Under these conditions, the detection limit was approximately 2 x 10(5) viral particles, after 40 amplification cycles performed with the Taq polymerase.

Aplastic anemia complicating orthotopic liver transplantation for non-A, non-B hepatitis

Aplastic anemia developed in 9 of 32 patients (28 percent) undergoing orthotopic liver transplantation for acute non-A, non-B hepatitis, at one to seven weeks after the procedure. No patient previously had evidence of hematologic dysfunction or conditions known to be associated with aplastic anemia. No other cases of aplastic anemia were identified among 1463 patients undergoing liver transplantation for all other indications at the four centers participating in the study (chi-square = 415, P less than 0.001; 95 percent confidence interval for the incidence of aplastic anemia after transplantation for non-A, non-B hepatitis, 13 to 44 percent, vs. 0.00 to 0.13 percent for all other indications). The operative and postoperative treatment of these patients was not otherwise different, indicating that the aplastic anemia was a complication of the hepatitis, not of the transplantation procedure. Four of the nine patients died of complications due to infections. Three of the surviving patients have been followed for less than six months, one for one year, and one for two years. The two patients followed the longest have recovered marrow function to an appreciable degree, and two of the others have evidence of early recovery. We conclude that patients undergoing orthotopic liver transplantation for non-A, non-B hepatitis are at a high risk for the development of aplastic anemia.

Detection of hepatitis B virus sequences in serum by using in vitro enzymatic amplification

In vitro enzymatic amplification was applied to detect hepatitis B virus (HBV) DNA sequences in serum. This technique, known as the polymerase chain reaction (PCR) was used to amplify a 128 bp DNA fragment including a 112 nucleotide long sequence complementary to a region in the S gene of the HBV genome. Amplified samples were subjected to spot-test hybridization and scintillation counting using a 32P-labeled oligonucleotide probe. A kinetic study, performed for 4 to 32 PCR cycles with a viral particle preparation, showed a time-limited exponential accumulation of the specific amplified DNA fragment. Amplification yield after 32 cycles was at least 4 X 10(6) with a detection limit equal to 3 X 10(2) viral particles per ml of serum. As the reliability of the PCR technique was greatest for 24 PCR cycles, these conditions were used to develop a quantitative test with a detection limit of 4 X 10(4) viral particles per ml of serum. Results of this test were perfectly correlated with those obtained from the classical spot test without amplification. Ethidium bromide stained agarose gel and Southern blot analysis confirmed the specific amplification of the 128 bp HBV DNA fragment.

Non-radioactive hepatitis B virus DNA probe for detection of HBV-DNA in serum

A diagnostic test has been developed to detect hepatitis B virus (HBV) DNA in human sera. This test involves a dot-blot technique in which non-radioactive nucleic acid labelled with 2-acetylaminofluorene (AAF) is used as probe. Two series of human sera from 228 blood donors and 113 HBsAg chronic carriers were tested by hybridization with the same DNA probe labelled either with AAF or with 32P. A correlation between the techniques was observed for 328 sera (96%), and using the non-radioactive test it was possible to detect 56 (86%) of the 65 HBV-DNA-positive patients. A comparative study of the HBeAg/anti-HBe status and the presence of HBV-DNA was carried out on the sera from 113 HBsAg chronic carriers, 65 of which were positive for HBeAg and 29 of which were positive for anti-HBe antibodies. With the AAF test, 44 of the HBeAg-positive sera were positive, while 5 of the anti-HBe-positive sera were positive. This study shows that, although this non-radioactive test is slightly less sensitive than the radioactive hybridization assay (RHA), it can be used for a survey of HBV carriers. Dissociation of the viral multiplication and the HBe/anti-HBe status was identified with the AAF test as well as with the RHA. It would therefore appear that the AAF test described here may be used for the extensive survey of HBV multiplication.

Specific expression of hepatitis B surface antigen (HBsAg) in transgenic mice

Two transgenic mice were obtained that contain in their chromosomes the complete hepatitis B virus (HBV) genome except for the core gene. These mice secrete particles of HBV surface antigen (HBsAg) in the serum. In one mouse, HBV DNA sequences that had integrated at two different sites were shown to segregate independently in the first filial generation (F1) and only one of the sequences allowed expression of the surface antigen. Among these animals the males produced five to ten times more HBsAg than the females. A 2.1-kilobase messenger RNA species comigrating with the major surface gene messenger RNA is expressed specifically in the liver in the two original mice. The results suggest that the HBV sequences introduced into the mice are able to confer a tissue-specific expression to the S gene. In addition, the HBV transgenic mice represent a new model for the chronic carrier state of hepatitis B virus infection.

Hepatitis B virus DNA in patients with chronic liver disease and negative tests for hepatitis B surface antigen

We assessed the presence of hepatitis B virus (HBV) DNA in liver or serum samples from 134 patients with hepatitis B surface antigen (HBsAg)-negative chronic liver disease, including 20 with hepatocellular carcinoma. HBV DNA sequences were detected in 52 of the 88 liver samples (59 per cent), including 17 of the 20 samples from patients with hepatocellular carcinoma. Presumably "replicative forms" of HBV DNA were detected in only 5 of the 88 liver samples, 3 of which were from patients with no serologic marker for HBV. In most of the liver samples the DNA patterns were consistent with the presence of HBV or a closely related virus. Of the 105 serum samples tested, HBV DNA sequences were identified in 10 (9.5 per cent), 6 of which had no HBV serologic marker. Moreover, HBsAg-associated determinants were detected in 5 of 17 patients who were positive for HBV DNA and in none of 14 patients who were negative. This study demonstrates the high frequency of HBsAg-negative HBV DNA-positive viral infection of the liver and suggests that multiplication of HBV may occur in the absence of any conventional serologic marker for HBV.

Detection and characterization of hepatitis B virus DNA in serum of HBe antigen-negative HBsAg carriers

Sera from 153 Israeli patients in various stages of hepatitis B virus (HBV) infection with undetectable hepatitis Be antigen (HBeAg) were studied for the presence of HBV DNA in the serum by molecular hybridization. HBV DNA was detected in 10 patients: 3 with acute hepatitis, 4 asymptomatic hepatitis B surface antigen (HBsAg) carriers, 1 with chronic active hepatitis, 1 with cirrhosis, and 1 with mixed cryoglobulinemia. HBV DNA was detected in 7 of 10 HBeAg-positive control samples tested. Hybridization analysis was used for quantitative comparison of HBV DNA levels in serum. HBV DNA levels, found in HBeAg-negative patients sometimes exceeded the levels found in HBeAg-positive patients. Restriction enzyme analysis of serum HBV DNA from four HBeAg-negative samples gave undistinguishable digestion patterns as compared to 3 HBeAg-positive samples. However, heterogeneity in HBV DNA restriction fragments was detected among HBV genomes in sera of HBeAg-positive samples. These data demonstrate that HBV DNA may be present in the serum at various stages of HBV infection, regardless of HBeAg detection. Failure to detect HBeAg in these patients does not necessarily reflect low serum levels of viral particles, or the occurrence of HBV genome variants.

Chronic lobular hepatitis: a clinicopathological and prognostic study

A series of 80 patients with chronic lobular hepatitis (CLH) was reviewed clinically and histologically to demonstrate etiology, clinical presentation, course, and prognosis of this disorder. Data from our study indicate that CLH in Taiwan is a disease of viral origin, mostly hepatitis B (67.5%) and some non-A, non-B. It occurs predominantly in young males (81.3%); frequently commences as acute viral hepatitis (57.5%); and has clinical and laboratory features similar to convalescent viral hepatitis or even indistinguishable from full-blown acute viral hepatitis. Clinical and histological follow-up study indicate that CLH may extend for several years with remissions and relapses. No evidence of progression to cirrhosis was observed at least in a 4 1/2-year period of follow-up. It is concluded that CLH is a persistent but nonprogressive disease although the number of non-A, non-B CLH is too small to ascertain its nonprogressive course. The prognosis is generally good, and no specific therapy is required.